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Hi,

I have a question about transformation of coordinate system in BK. I have a ADCIRC .14 mesh file (generated from OceanMesh2D) imported to Blue Kenue (v3.3.4) and would like to do a spatial projection from wgs84 to UTM.

After I imported the .14 mesh, assigned it to UTM Zone 30 with ellipsoid of WGS84 (I'm aware that no transformation is performed in this stage) and clicked Ok->Apply, there is no apparent change of mesh. Both geometry and mesh still look a bit distorted and 'flat'. Is this because BK cannot convert coordinate system? Consider the fact that I have to interpolate bathymetry and bottom friction (which are in UTM coordinate system) to the mesh. What do you recommend the solution for this? Thanks a lot.

Hi,

First of all, some definitions...
1. wgs84 is an ellipsoid definition. (shape of the planet)
2. UTM is a coordinate system. (spatial coordinates in meters relative to the origin of a patch of the earth defined by the UTM zone)

Asking to convert wgs84 to UTM is not logical.

From the way you pose your question I'm going to assume that the ADCIRC mesh coordinates are in Lat/Long and you want them in UTM.

Steps...
1. After loading the .14 file, Assign the Coordinate system LatLong, Ellipsoid WGS84. Press OK

2. Now choose UTM as the coordinate system from the dropdown and set Zone 30. Press Apply
and you're done.

Hope this helps... Martin

As a side note; I just searched in the pdf Reference Manual that comes with Blue Kenue 3.12.7-alpha (see Help Menu) in order to see what happens.

• The first hit for "WGS84" is on page 22 in Table 1.2 "Ellipsoids supported by EnSim and their associated parameters".
• The first hit for "UTM" is slightly earlier, on page 20 in Section 1.6.3.4.2 "Coordinate Systems".

BOTH first hits lead you to the correct explanation.

Tip for the future:

• First, search the Reference Manual
• Second, post to the forum if you can't find it in the Reference Manual... and let us know what words you used while searching. This will help us to improve the Reference Manual for future searches.

Thanks,
Alan

FYI

I've also added the general tip about searching to #12464.

Kindly,
Alan